Frank m



(No Model.)

P. M. LEAVITT. ADJUSTABLE POWER PRESS.

No. 518,847. Patented Apr. 24, 1894.

WITNESSES:

4, By his Altameys, W .Qrmn

UNITED STATES PATENT, OFFICE.

FRANK M. LEAVITT, OF BROOKLYN, NEW YORK, ASSIGNOR TO THE E. W. BLISS COMPANY, OF SAME PLACE.

ADJUSTABLE POWER-PRESS.

SPECIFICATION forming part of Letters Patent No. 518,847, dated April 24, 1894. Application filed July 8, 1893. Serial No. 479,916- (No model.)

To all whom it may concern:

Be it known that I, FRANK M. LEAVITT, a citizen of theUnited States, residing at Brooklyn, in the county of Kings and State of New York, have invented certain new and useful Improvements in Adjustable Power-Presses, of which the following is a specification.

This invention relates to power presses wherein a reciprocating sliding head or platen is actuated from a crank shaft through a pitman or connecting rod which is adj ustablein length in order to bring the stroke of the head closer to or farther from'the bed of the press. In such presses for especially heavy work, or where a longhead is required, it is common to construct them with double cranks and pitmen, the two pitmen engaging the head near its opposite ends. In the operation of such presses, difficulty has been found in efiecting an equal and simultaneous adjustment in.

length of both the pitmen, notwithstanding that various ratchet devices have been proposed and used for communicating the adj ustment from the adj listing screw of one pitman to that of the other. .In such devices there is no positive connection between the means for communicating adjustment and therespective screws, so that it often happens that one screw will be driven a part of a revolution in advance of the other, thereby giving the two pitmen unequal length and ca'nting the head in its slideways.

' My invention is designed to provide a simple and positive connection between the two pitmen in order that their adjustment shall necessarily be effected simultaneously, and so as to prevent the occurrence of any inequality in length of the pitmen. To this end the pitmen are constructed with two opposite parts or sections reciprocally sliding on each other telescopically or otherwise, and adjusted relatively to each other by an adjusting screw, and the screws of the two pitmen are provided with bevel-gears fixed to them and geared together. through the medium of a transverse shaft extending between the pitmen, and having bevel-gears or pinions on its opposite ends meshing with those on the screws, so that in order'to adjust the length of the pitmen it is only necessary to rotate this intermediate shaft in one direction or the other, whereby both pitmen are elongated'or shortened in positive manner a crank shaft 0, which is suitably driven and which has two cranks c a connected by pitmen D D to the reciprocating head or platen E of the press, which slides on guidesor slideways a a carried by the uprights of the frame. Generally speaking this is the usual construction of a double-crank power press.

Each pitman D consists of two relatlvely adjustable sect-ions b and d, the formeradapted at its upper end for engagement with the "crank or eccentric 0, while the latter at 1ts lower end has pivotal connection with the head E. The two parts or sections b d are constructed to slide longitudinally relatively to one another, in order thereby to vary the length of a pitman as a whole. The preferable construction is that wherein one of the parts I) enters and slides telescopically in the other d. For effecting their adjustment, a screw e isintroduced which has relative engagement with the two parts of the pitman, preferably by being constructed w1th a rotative or swivel connection with one part, and with a screw threaded connection with the other part." As shown, one end of this screw has fixed on it a bevel-gear f which is confined in a socket or chamber g formed in the part (1, while the threaded portion of the screw enters the part b, which is made tubular and which is formed with internal screw threads engaging the threads on the screw, so that by turning the screw the section d is slid up or down over the section b to shorten or lengthen the pitman. The gear f by being confined within the recess 9 and by being fixedly attached to the screw, will prevent any longitudinal movement ofthe screw relative to the section cl. The gear f is keyed or otherwise so connected to the screw as to be compelled to turn with it. This description or one pitman D will serve for both, since they are preferably identical in construction. For insurlng a simultaneous adj ustmentI connect them together through the medium of a transverse shaft F extending from one pitman to the other, on the ends of which are fixed bevel pinions h h which mesh with the respective bevel gears f f. In the construction shown where both bevel gears f f engage with the lower sides of the pinions 72, h, the screws 6 e are necessarily threaded with right and left threads respectively. By inverting one of the gears f, however, the two screws mightbe both threaded in the same direction.

The shaft F might be variously constructed, but for convenience of construction or assembhng of the parts and ease of operation, I prefer to construct it as shown of a divided hollow sleeve i, and two short shafts j j, the latter being constructed integrally with or securely fastened to the pinions h h. The sleeve 2 is divided diametrically in order that 1ts halves may be closed together upon the ends of the short shafts j, and be clamped or drawn together by means of bolts is to secure the sleeve firmly on said shafts, so that the three parts j tj shall be so securely fastened together as to turn as one part. On the middle of the sleeve '5 is formed an enlargement or drum m which is pierced with holes at intervals to constitute a sort of capstan, so that by lnsertlng a bar inany of these holes the shaft F may be easily turned for adjusting thelength of the pitmen. Inasmuch as the pinions It must enter the chambers or recesses g in the pitmen, and in order that they can be inserted therein or removed therefrom after the pitmen are in place, I form the recesses with openings on their sides toward each other sufficiently large to admit the insert on or removal of the pinions h and gears f, and for closing these openings and providing bearings for the shafts j, I provide separate p1eces or bushings p p which, after the pinions h and their shafts j are in place, are sllpped over the shafts and bolted or screwed to thBSldG of the sections cl of the respective pitmen so as to close the openings into the recesses g. The construction is then completed by applying the opposite halves of the sleeves c on the protruding ends of the shafts j andbolting them firmly together so as to tightlyembrace the shafts. The particular construction described has the advantages of completely closing and concealing the adj usting screws and gears so that they are protected from injury, and of providing a simple and easily applied construction for the interveningshaft F.

In the practical application of my invention, the details of construction herein specifically described may be considerably varied without departing from its essential features. It will therefore be understood that I do not limit myself in all respects to the specific details of construction herein shownand described.

Those features which I believe to be essential to my invention are hereinafter defined in the claims.

I claim as my invention the following-defined novel features, substantially as hereinbefore specified, namely:

1. In a double-crank power press, the combination with the crank shaft and sliding head, and two pitmen connecting the cranks with the head, each pitman constructed in two sections-so as to be adjustable in length, with a longitudinal adjusting screw for relatively adjusting them, of the means for effecting the simultaneous adjustment of the two pitmen, consisting of a transverse shaft extending betweenthem, and supported by them, so as to participatein their movements and gears on said shaftand on the respective screws whereby the turning of said trans verse shaft turns both screws to like extent.

2. In a double-crank power press,the.com-

bination with the crank shaft and sliding head, and two pitmen connecting the cranks with the head, each pitman constructed' in two sections so as to be adj nstable in length, with an adjusting screw for relatively adjusting them, the twoscrews having respect ively right and left threads, of the means for effecting the simultaneous adjustment of the two pitmen, consisting of a transverse shaft extending between them, and bevel gears on the opposite ends of said shaft, and similarly-arranged bevel-gearsmeshing therewith fixed on the respective screws to rotatelthe two screws in opposite directions.

3. In a double-crank power press, the combination with the crank shaftand sliding head, and two pitmen connecting the cranks with the head, each pitmanconstructed in two sections the one sliding telescopically;

into the other and the one formed with internal screwthreads, and a screw having threads engaging said internal. threads and:

itself swiveled to the opposite section so as to be adapted to rotate therein, but incapable of longitudinal motionindependent thereof, and means for effecting the simultaneous ad of the two pitmen consisting of a.

justment transverse shaft extending between them, and gears on said shaft and on the respective screws.

4. In a double-crank power press,the'combination with the crankshaft and sliding head, and two pitmen connecting the cranks with the head, each constructed in two sec tions so as to be adjustable in length, with an adjusting screw for relatively adjusting them, and bevel gears fixed on the respective screws, of a transverse shaft extending between the pitmenconsisting of endshaft sections having bevel gears meshing with those on the screws, and an intermediate sec- Zion detachably connected to said end secions.

5. In a double-crank power press, the cornbmatlon with the crank shaft and sliding head, of two pitmen each constructed in two sections, with an adjusting screw for relatlvely adjusting them, and bevel gears fixed on the respective screws, and a transverse shaft F extending between the pitmen consrst ng of end shaft sections jj carrying bevel pinions h h meshing with said bevel gears, and an intermediate sleeve i constructed to be detachably connected to the shaft sect1ons j j.

6. In adouble-crank power press, the combrnation with the crank shaft and sliding head, of two pitmen D D each constructed 1n two sections b d, the latter formed with a recess 9 open at one side, an adjusting screw e for relatively adjusting said sections, and a bevel gear f fixed on said screw within said recess, and a transverse shaft extending between the pitmen comprising end shaft sections 3 and bevel pinions h, and a bushing 10 

